Navigation systems have become increasingly popular in recent years. A navigation system consists of a small electronic device that aids a driver of a vehicle to reach a desired destination. Navigation systems are particularly useful for people visiting areas they are not familiar with.
Navigation systems operate by knowing where the navigation unit is positioned by using Global Positioning Satellites (GPS) and by applying that position to a context provided by a map and by a desired destination. The navigation system can then suggest how the driver of a vehicle (for example) should act (e.g. turn right in 500 metres) to get to the desired destination according to possible route alternatives (defined in the map) and personal preferences (e.g. avoiding motorways).
The context can be augmented using additional information such as broadcasts of traffic information (traffic jams on certain routes). U.S. Pat. No. 5,610,821 discloses a system for determining optimal vehicle routes using current traffic flow information. The system receives current traffic flow information from a number of individual vehicles and uses this information to identify when a traffic flow problem exists. Once the system has identified that a traffic problem exists, it re-calculates a new route based on the information received from the vehicles. The system therefore continuously monitors the traffic flow of a road network and provides alternative routes when traffic flow problems are identified.
The system of U.S. Pat. No. 5,610,821 relies upon receiving dynamic feedback traffic flow information from the individual vehicles, but often local knowledge is the only way to choose one route over another in terms of efficiency. Local knowledge, for example, could be that cars often double-park on a particular street, reducing its effective width, road conditions, such as potholes, and so on.
Navigation systems exist which are capable of gathering historical information concerning routes taken by a number of individual vehicles. Such systems rely on a central database to analyse and store the historical information of all the participating vehicles. The central database can therefore suggest an improved route to a vehicle based on the analysis of the information gathered from the participating vehicles. However, such systems are often troublesome and costly to administrate. Furthermore, as the central database analyses historical information received from a number of different types of vehicles (e.g. delivery trucks, taxis, motorbikes etc.), the routes suggested by the system are often inappropriate for a specific type of vehicle. For example, a route which is appropriate for a motorbike is often not appropriate for a truck, and vice versa.
Navigation systems, such as those discussed above, are therefore limited in that they are expensive to administrate and often cannot suggest the optimal route to the driver of a specific type vehicle.